2 Stroke fishtailing

[Eham]

I have a 66cc set up on a 26" beach cruiser, it has less than 50 miles on it right now. When riding the other day back wheel began to fish tail pretty, I was surprised I didnt lay it down. When started I was going about 20mph on flat dry road. After stopping when I started up again it started fish tailing at any speed above 5mph. I need some advice as to why this could happen and how to prevent it in the future.
Thanks

 

[Frankenstein]

How's the air pressure in the tire? How's the tread on the tire...

 

[bakaneko]

either that or the rear sprocket is not centered correctly across the nuts or worse the rear tire bearings are loose or destroyed. try lifting the back wheel and spinning it to see if there is a wobble from the wheel.

 

[Frankenstein]

either that or the rear sprocket is not centered correctly across the nuts or worse the rear tire bearings are loose or destroyed. try lifting the back wheel and spinning it to see if there is a wobble from the wheel.

Fishtailing is when the rear wheel slides out from under you right?

 

[crassius]

did you check that force of motor chain didn't pull the axle forward on that side?

 

[Eham]

Tires are brand new less than 50 miles and just put air in earlier that day. Back wheel was shifting side to side. Is it possible sproket was center properly then changed after limited riding?

Ill have to check for wobble and if chain pulled axle. How would i been able to tell if it pulled axle?

 

[bakaneko]

err, yeh i mean i was just going off of his description of the wobble. i had the same issue with my bike when the bearings started to give or the sprocket wasn't on and aligned properly. low speeds it seems fine and then at higher speeds its like you are on a carnival ride with the wobble.

 

[gary55]

Check youtube, tightening bearings on bicycle hub.

 

[James White]

Are you using spoked wheels? If so make sure to keep them trued. Will cause wobble. I use mags only, no problem with having to true them. And they look cool.

 

[Eham]

Thanks for all the help. Looks like it was combo of chain being too loose and nut on end of axel coming loose. Seemed to ride ok today